1. Field of the Invention
The presently disclosed subject matter relates to a functional film and a method for manufacturing the functional film, and especially to a functional film and a method for manufacturing the functional film, the film including a laminated structure obtained by feeding a film from a film roll manufactured by taking up a coating film formed, and forming on the coating film an inorganic film.
2. Description of the Related Art
In various devices such as an optical element, a display device such as a liquid crystal display and an organic EL (electroluminescence) display, a semiconductor device, and a thin-film photovoltaic cell, there are used functional films such as a gas barrier film, a protective film, an optical filter, and an antireflection film.
Further, for manufacturing these functional films, there is used a film-forming technology based on a vacuum film-forming method such as sputtering, and plasma CVD (chemical vapor deposition). In order to form a film by a vacuum film-forming method efficiently and with high productivity, it is also practiced to form a film continuously on a long substrate.
A method for manufacturing the functional film will be described. While feeding a long support continuously from a film roll, a coating liquid is applied on the support, dried, and cured to form a coating film. The support, on which the coating film is formed, is taken up to manufacture a film roll. Then, the film roll having the coating film formed thereon is set in a feeding section of a vacuum film-forming apparatus, and the support is continuously fed from the film roll to a film-forming chamber. In the film-forming chamber, an inorganic film is formed on the coating film, and the film, on which a laminated structure including the coating film and the inorganic film is formed, is taken up to manufacture a film roll. As an apparatus to carry out this film-forming method, there is known a so-called roll-to-roll film-forming apparatus. By carrying out the film-forming step for the coating film and the inorganic film a plurality of times using this film-forming apparatus, a functional film having a plurality of laminated structures is manufactured.
In the above-described manufacturing method, in order to make the quality of the functional film uniform by preventing misaligned winding when forming an inorganic film, in Japanese Patent Application Laid-Open No. H8-92727, there is described a method whereby a film roll having a winding hardness of 70 to 95 is set in the feeding section of the vacuum film-forming apparatus, and an inorganic film is continuously formed on the support.
Furthermore, in Japanese Patent Application Laid-Open No. H6-60374, there is described that a winding body of a long plastic film is inserted in a vapor deposition chamber, and then the vapor deposition chamber is depressurized to 20 Torr for 2 minutes or longer. Then, the chamber being evacuated to the usual vapor deposition pressure, and then a ferromagnetic alloy or an alloy is adhered on the plastic film by a vapor deposition method.